Maccamp Boston is this weekend - and I’m going to go !

I’m not quite sure what I’ll talk about (if asked) probably iOnTV (which I’ve done a bunch of work on recently - though it’s not reflected on the website).

Oh - and I got VMware to donate some copies of Fusion for a raffle too !

Dith Pran a survivor of the terrible Khmer Rouge regime in Cambodia died today of cancer.

Roland Joffe’ 1984 movie The Killing Fields tells the story of Dith Pran and an american journalist who tries to help him. It’s one of my all time ‘favourites’. Though I use that word with caution because it’s such a moving movie of a terrible episode in humanities history. The movie, and it’s particularly haunting soundtrack by Mike Oldfield has always stuck with me.

Sadly Haing S Ngor the actor who portrayed Dith Pran died in 1996 apparently the result of a homicide.

Craig Hockenberry (Iconfactory & Twitterific) is looking to encourage more developers to request Apple to support the use of Mac OS X Client (Desktop) virtualization and not just the Server version of Mac OS X :

http://furbo.org/2008/03/21/vote-for-virtualization/

Of course I have a vested interest in this and am not without bias on the issue - but all the same he raises valid points…

There’s been some ‘grumbling’ (here and here) about some of the restrictions that are placed on application developers and their products if they use the iPhone SDK.

Many of the commenters seem concerned that the SDK is much more restrictive than ‘regular desktop’ development, with restrictions on running in the background, a lack of access to certain parts of the platform, and pieces of functionality present in desktop Mac OS X but missing from Cocoa Touch.

Why are things so different ? Technical challenges ? No. The reason - in two words is: Legal Liability.

I think Apple is very concerned that there is a danger someone would try to use their iPhone in an emergency (to dial 911) and have it fail because of a failure (or out of control) third-party application. If that happens and lawyers get involved I don’t think they’re going to  go after small  one-person software developers with buggy code. Rather they’ll go for the deep pockets at Apple.

Yes Mac OS X uses protected memory, and is a pre-emptive operating system. But it’s still vulnerable to people using too many resources and there are places in the OS where the failure of one application at the wrong time can lead other applications to fail (for example Disk Notification on the desktop  Mac OS X can cause Finder to stall if you fail to respond to the notification request in a timely manner).

Personally I’m grateful for a little care, attention and large walls in this space - my phone is probably more important than my desktop, especially in an emergency, making sure it’s always there when I need it is very important.

Part of the iPhone SDK is a requirement to spend $99/year if you wish to distribute your application through the iTunes Store.

The $99 also gives you the ability to load your application into your own phone for testing without needing to use the store. Apparently it does this by giving you a certificate which you can use to sign your application, the same certificate needs to be installed into the phone for the application to run.

This is part of Apples mechanism to ensure that only approved (blessed) applications will be distributed through the store - apps on the store will be signed with a different certificate that Apple will control and that certificate will be installed on all iPhones running V2.0 of the iPhone OS.

What about beta testing your application on a larger pool of users than just your phone - testing is always a good thing - but right now it’s unclear how you can distribute your application to a pool of testers and let them install it. Using the store won’t be a good thing because that exposes the app to everyone. Require every tester to have paid $99 for the tools to self-sign (as it’s called) and install the app on their phone ? That seems expensive. Distribute your certificate with each app and have testers install it alongside the app ? Better - but still the question of exactly how is the app installed.

How to test the fruits of your labours seems quite unanswered right now !

One of the things that Google announced with Android (though they’ve revised the rules once already) was a competition with between $25,000 and $275,000 in prize money for the best mobile applications on Android.

Today’s ‘One More Thing…’ announcement from Steve Jobs during the iPhone SDK event was for John Doerr from the VC Partners Kleiner Perkins Caulfield & Byers announcing that they’ve created a $100 million fund to invest in the development of applications for the iPhone. You can find the FAQ here - Kleiner has one of the better track records of picking good tech firms to fund. Gaining their funding would be a huge leg up for any developer !

Frankly I prefer Apple’s approach - it seems a little more professional and a little less like a competition for students !

A story doing the rounds of Slashdot, OSNews et al today is this one from ComputerWorld Australia. James Cameron (no not that one) is testing the OLPC mesh networking in the Australian Outback where he lives.

In one of those small world moments - James is a former colleague of mine from Digital Australia. Though at the time we were working together he was living considerably closer to Sydney.

The mesh networking in OLPC XO is one of the features that I think sets it apart from some of the other ‘cheap’ notebooks that have become common recently. We bought an OLPC XO for Sylvie at Christmas in part because we felt it as a good donation to a worthy cause and also so she could have a computer of her own to interact with. The Mesh networking is not something we’ve tried since I don’t have a second machine or any of the other requisite hardware (and we have pretty ubiquitous WIFI at home too).

Although I might have ordered a new zippy MacBook - my old PowerBook is still proving its use: highlighting pieces of code that are just too slow.

In the iOnTV UI application the schedule grid (list of what’s on) is a critical part of the main window. I noticed that as the database of program information got larger scrolling performance in the schedule grid (going backwards/forwards in time) was terribly slow on my PowerBook.

A little time with Shark showed that I was spending 80% my time in the ‘fetch schedules on a station between two times’ method. This method used a simple predicate to fetch only those schedule details fulfilling the arguments :

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"((station == %@) AND (time >= %@) AND (time <= %@)) OR ((station == %@) AND (time < %@) AND (endTime > %@))", self, startDate, endDate, self, startDate, startDate];

A little thinking about it and I realized that the logic was overly complex and could be simplified :

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(station == %@) AND (((time >= %@) AND (time <= %@)) OR ((endTime >= %@) AND (endTime <= %@)))", self, startDate, endDate, startDate, endDate];

I don’t need to compare against the station more than once - start with everything on this station, and then consider only those things that start between the two times or end between the two times.

Result ? The fetch is now less than 10% of the CPU usage when changing the start time in the schedule grid ! Much better ! I still have a couple more optimizations to make - but watch those predicates !

One of the more dangerous traditions at Be was that of ‘roof disposal’.

In the late 1990’s Flat Screens were completely unheard of other than on laptop PCs. Old CRT monitors were everywhere - and they weren’t necessarily very reliable. At Be CRT Monitors that died would usually end up in a pile in a cube or hallway and be labeled ‘roof disposal’.

Then a few times a year the actual act of ‘roof disposal’ would take place :

Or for an alternative view :

And yes - we knew that monitors contain a lot of pretty nasty chemicals, and yes we were careful to sweep up throughly afterwards.Also these events took place on the weekends when the Charles Schwab office on the ground floor was closed - and lookouts were posted. Not that it prevented JLG from coming out of the building and seeing the cleanup effort and saying “So that’s what Roof Disposal means”.

I’d been looking for these videos for a long time (even trying to resurrect an old BeOS installation to recover them - they were included on the BeOS R5 release CDs) - my thanks to a colleague at VMware who found them on YouTube and sent me the link.

Shawn Morel is one of the developers on the Fusion Team here at VMware.Last year he gave a presentation (along with local Boston Mac Developer Daniel Jalkut) at the C4[1] developer conference. Wolf Rentzsch the conference organizer has started putting videos of the presentations on-line, he just posted the video of Shawn’s presentation. Daniels presentation was posted last week.